"Utilizing whole-exome sequencing we found two novel MTR variants c.871C>T (p.Pro291Ser) and c.1771C>T (p.Arg591*) in Patient 1 and a ABCD4 homozygous variant c.423C>G (p.Asn141Lys) in Patient 2. Our study identified the first Cobalamin Gpatient and cobalamin J patient in mainland China and highlighted comprehensive metabolic analyses and genetic tests in patients suspected of cobalamin defects"xsd:string